Lens grinder



Nov. 111, 1952 R. ALLEN ETAL LENS GRINDER Filed June 16. 1949 4Sheets-Sheet l FIG.

INVENTORS ROBERT E. ALLEN Nov. M, 1952 R. E. ALLEN ETAL LENS GRINDER 4Sheets-Sheet v 2 Filed June 16. 1949 I INVENTORS ROBERT E. ALLEN\[VILLIAM F UTZINGER Nov. 11, 1952 R.- E. ALLEN EI'AL LENS GRINDER 4Sheets-Sheet 3 Filed June 16. 1949 F UTZINGE?I (4775x 9 r'TTfi:

INVENTORS ROBERT E. ALLEN WILLIAM BY Nov. M, 1952 R. E. ALLEN ETAL LENSGRINDER 4 Sheets-Sheet 4 Filed June 16, 1949 4 d 4 8 8 w '0 l2 un 8 L 59 [1 HH W d m FIG. IO

FIG.

INVENTORS ROBERT E. ALLEN R F- G Z W! M m L- I- m M Bl J Patented Nov.11, 1952 UNITED STATES PATENT OFFICE LENS GRINDER Robert E. Allen andWilliam F. Utzinger, Dayton,

Ohio, assignors to Univis Lens Company, Dayton, Ohio, a corporation ofOhio Application June 16, 1949, Serial No. 99,372

8 Claims. 1

This invention relates to optical lens grinding machines, and moreparticularly to a machine for edging a lens blank.

The invention, in general, is embodied in a machine having a lens blankholding means, an abrading element for grinding the edge of the lensblank, pattern means for determining the peripheral shape of the lensblank, means for controlling the movement of these members in apredetermined manner, and means for driving the machine.

One of the objects of the invention is to provide a support for mountingthe lens blank element so that the peripheries of the lens blank and theabrading element can be brought into contact. This support is freefloating and provides for moving the lens blank element toward and awayfrom the other element. The support also cooperates with means forcausing relative translatable movement of these elements while theirperipheral surfaces are in abrading relation with one another.

A feature of this construction is that a small, lightweight and compactmachine can be provided which is adapted for either dry edging plasticlenses with an abrasive belt, for example, or for grinding glass lenseswith a small and inexpensive diamond wheel. It has been foundimpractical from a cost standpoint to equip a standard lens edgingmachine with a diamond wheel of the usual or regular size. Theconstruction here provided is adaptable for using an extremely smallsize of diamond wheel which is both practical and economical. With thelatter construction, the machine is equipped with a small pump andcoolant reservoir which replaced the suction pump provided to remove thedust or cuttings resulting from dry edging plastic lenses. Furthermore,in addition to cutting a square edge for rimless mountings, the machinecan also be adapted to edge lenses for frame mountings since it can cuta bevelled edge when provided with an abrading element which cuts aV-shaped section around the periphery of the lens blank.

An additional object of the invention is to provide an arm for rotatablysupporting the driven lens blank element, the arm being swingable on apivot means for movement of the lens blank element toward and away fromthe abrading element, as well as for longitudinal movement relative tothe abrading element. A feature of this construction is that the lensblank element and the pattern-means, for determining the peripheralcontour of the lens blank, can be swung so that the lens blank crossesthe abrading element with its axis of rotation parallel to the axis ofrotation of the abrading element, and while so moving the lens blank isfree to move in a direction at right angles to said axes of rotation inresponse to movement of the pattern means.

Another object of the invention is to provide a cam and cam follower, aspart of the pattern means, for controlling the movement of the lensblank element whereby the lens blank is gradually lowered into contactwith the abrading element. This feature of the construction prevents adeep out being taken too rapidly from the, lens blank, such as wouldoccur if the lens blank element under the full weight of the supportingarm remained continuously in contact with the abrading element. Inoperation, the lens blank while being edged is raised and lowered, withrespect to the abrading element, in response to movement of the camfollower. This movement prevents the lens blank from being heatedexcessively and its optical properties are not distorted. A furtherfeature resulting from this construction is that the lens blank is movedacross substantially the entire surface of the abrading element, thusassuring even wear across the entire peripheral surface of the abradingelement.

An additional object is to provide a driving means, such as a pulley andendless belt, for applying power from a prime mover to rotate the lensblank and associated mechanism, in which the belt pull or torque isapplied at a point which, when projected, lies in a plane extending atright angles to the axis of rotation of the pulley, and which plane alsoextends through the projected axis of rotation about which the pivotallymounted support for the lens blank element moves. The support is thusfree floating in that the support at all times pivots about a point inline with the belt pull.

It is also another object to provide pattern means for controlling theperipheral configuration of the lens blank, which comprises a cam memberand a pattern member, and which are translatably movable with respect toone another. Means in the form of a feed screw and an engaging elementare provided for causing movement between these members. A feature ofthis construction resides in having the feed screw driven from the sameshaft means provided for driving the pattern member. The feed screw isalso utilized to control the rate at which the lens blank is moved intoabrading relation with the abrading element- The regulation thuseffected prevents the lens blank from being cut to pattern size at arate which causes excessive heating thereof.

Other features of this invention reside in providing an abrading elementin the form of a drum adapted to receive an abrasive belt having asurface of silicon carbide grit or similar material. The drum is drivenat a high rate of speed, of the order of 5000 R. P. M., and the lensholder at a low rate of speed, of the order of 2 R. P. M. Also, ifdesired, the suction pump for removing the dust or cuttings from thegrinding operation can be driven from the same power source provided fordriving the lens blank, or a pump can be operated therefrom to circulatea coolant where a diamond wheel is used.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein preferred forms of embodiments of the invention areclearly shown.

In the drawings:

Fig. 1 is a top plan view of a machine embodying one form of the presentinvention;

Fig. 2 is a side elevational view of the machine shown in Fig. 1;

Fig. 3 is a front elevational view of the machine as seen from the rightside of Fig. 2;

Fig. 4 is a side elevational view, partly in section, of the switch andmounting mechanism therefor;

Fig. 5 is a broken, back elevational view, partly in section, showingthe pivotal connections between the arm and base, and a part of theshaft driving means, as seen from the left end in Fig. 1;

Fig. 6 is a broken, verticalrsectional view, partly in elevation,showing the lens holder, pattern means and feed screw as carried by thearm;

Fig. 7 is a diagrammatic view illustrating the positioning of the link,shaft and pulley relative to the pivotal connection between the link andthe base;

Fig. 8 is an elevational view of the cam and supporting bracket as seenfrom the right side in Fig. 3; and

Figs. 9 to 11 are diagrammatic views illustrating modified constructionsof the cam shoe and abrading element for bevel edging the edge of thelens blank.

Referring further to the drawings, the machine shown includes asupporting base It. A support, indicated generally at H, includes a linkI2, an arm member 13, and a second arm member 14 integral with member l3and at right angles thereto. One end of member l3, as seen in Fig. 5, ispivotallymounted within the U -shaped yoke IS.

A shaft i6 extends through member [3 and yoke [5. This shaft isjournalled at each end in the bearings [1. These bearings are mounted soas to be carried by both the yoke and member l3, as shown. There is apress fit of the bearing H in member 13 and a running fit of the bearing[1 in the yoke l5. Suflicient clearance is provided between the yoke andmember l3 to allow free swinging movement of member [3 about the shaftIS in a, plane at right angles to the base [0.

The yoke I5 is slidably mounted at the bottom on the seat 20 formed onthe base. A pair of oval shaped openings 2| extends through the top ofthe base and seat 20. The screws 22, Fig. 5, engage the bottom of theyoke l5 through these openings. These screws also connect the yoke tothe link [2 which, in turn, is pivotally connected with a screw at itsouter end to the base, as indicated at 24. Movement of the yoke l5 4 onthe seat 20 is controlled by the movement of the link [2 about the pivot24.

Transmission means is provided which comprises, in general, the shaftIt, a shaft 21 extending longitudinally through arm member l3, and aspindle shaft 28 carried by the arm member l3. These shafts arerotatably mounted and driven by a pulley 30 connected to the shaft 16.Shaft H5 drives shaft 21 through a worm 3| and gear 32, Fig. 5. Shaft21, in turn, drives shaft 28 through a worm 33 and gear 34, Fig. 6.Thrust bearings 35, Fig. 2, are provided at each end of shaft 21. Theshaft 28 is journalled for rotation within the bearings 36 and 31 whichextend through the inner end of arm member l3. Power is transmitted fromthe motor 38, Fig. 2, which is provided with a driving wheel, throughthe belt 39 from the driving wheel to the pulley 30.

The axis of pivot 24, when projected upwardly, substantially intersectsthe peripheral edge of the pulley 30 substantially most remote from thefree end of arm I3 and from the driving pulley of motor 38. Referring tothe diagram of Fig. I, the arrangement of the arm members, i. e., link12, shaft 16 and pulley wheel 30 with respect to the pivot 24 are shown.This construction provides for a free floating arm which is unaffectedby the pulling action of the belt 39 on the pulley 30 and shaft IS. Theforce or pull of the belt 39 is thus applied in the direction of thearrow 41'], Fig. 7, and at a point in the plane extending through thepulley 30 at right angles to its axis of rotation and through theprojected axis of rotation of the pivot 24. The application of thisforce in that plane does not cause a turning or moving force to beexerted on the members l3 and I5. The arm i4 is thus free to swing in aplane parallel to the top of base [0. Furthermore, with thisconstruction the length of arm I3, 1. e. the radius of the arc throughwhich the arm l4 swings parallel to the top of base it], can be made amaximum within the prescribed size limits of the machine. The axes ofrotation of the lens blank holder, pattern means and the abradingelement, as hereafter described, can thus be maintained in substantiallyparallel alignment during the cutting or edging operations. Thisconstruction also provides for leading the belt 39 from the motordriving pulley onto the pulley 30 at a point which does not swing out ofthe plane extending through the pulley 30 at right angles to the axis ofrotation of the pulley 3i] and through the projected axis of rotation ofthe pivot 24. The belt 39 thus remains on the pulley 3!) when thesupporting members l3, Hand 15 swing about the pivot 24.

In the preferred construction an electric motor of about horsepowercapacity and capable of rotation at 5000 R. P. M. is provided. Thisspeed of rotation is reduced through the gearing mechanism provided sothat the shaft 28 rotates at a rate of about 2 R. P. M.

A lens holder is provided for mounting the lens blank 42, Fig. 3, inworking position. The holder includes a positioning member 43 which isreceived on the pins 44, Fig. 6, which project from the head 45 formedon the end of shaft 28. Member 43 thus rotates with the shaft 28. Aretractable pad 41 also forms part of the holder. This pad is positionedto engage the lens blank on the opposite side from member 43. The pad isfaced with a rubber washer 48 on the front and engages at the back witha ball bearing 49. Bearing 49 is rotatably mounted on the compressionshaft 5| and the pad 41 rotates with the lens blank. Shaft 5| isreceived within the bearing 52 carried in the outer end of arm member M.A pin 53, Fig. 6, on the head of shaft 5| projects through a slot in theedge of bearing 52. This pin prevents rotation of the shaft 5|. A coilspring 54 encircles the shaft and seats against the head at one end andagainst the inner end of bearing 52 at the other. This spring forces thepad 41 against the lens blank. The outer end of shaft 5| is threaded toreceive a knurled knob 55. This knob is adjustable and provides formoving the shaft 5| and pad 41 toward and away from the lens blank foreither positioning or removing the lens blank in the holder. A stop nut56 on the end of shaft 5| prevents the knob 55 from backing off theshaft. A set screw 51 retains the bearing 52 in the. arm.

A shaft extension member 6| is coupled to the end of shaft 28. Thismember is formed with pins 62 fitting in openings in the cam followerfor positioning the cam follower, indicated at 63 in Figs. 3 and 6,which forms part of the pattern means for determining the peripheralshape or contour imparted to the lens blank 42. In operation, a follower63 is used which has a peripheral shape or contour of either regular orirregular form, and to which form the lens blank 42 is patterned whenedged. The follower 63 is rotatably driven by member 6|. A threadedshank 64, projecting from the outer end of member 6|, extends through acentral opening in the follower. A tapered and externally threadedsection in the form of a feed screw 61 is threadedly connected to theshank 64 and driven thereby from shaft 28. The body of the screw isthreaded as shown at 61a, Fig. 1, and the head knurled, as indicated at61b, Fig. 6, to facilitate mounting on shank 64. Screw 61 retains thefollower 63 on the pins 62. The outer end of the screw forms a bearingarea 68 having a flanged head 69.

Referring further to Figs. 1 and 4, the base In is formed with a boss1|. This boss is drilled to receive a spring pressed cap 12. At rightangles to this-bore, the boss is drilled to receive a short rod 13 whichfastens a hinge member 14 to the boss. The hinge carries the knife armor lever 15 to which the knife blade 16 is adjustably attached. The edgeof the blade 16 is bent inwardly, as shown, and forms an element adaptedto engage the threads on the feed screw 61 when arm member I4 is inoperating position. The spring pressed cap 12 bears against the lowerend of the pivotally mounted lever 15 and holds the knife blade 16 inengagement with the threads on the body of the feed screw. An arm 18 isconnected to the lower end of the lever 15. This arm extends through anopening 19 in the top of the base H). A switch 86 having a push button80a is provided to control the startingand stopping of motor 38. Switch80 is open when the button 80a is depressed. Thus, when the arm 4 is setso that the threads on the feed screw 61 engage with the blade 16, thelever 15 is pivoted inwardly at the bottom, i. e., moves clockwise andagainst the cap 12. This movement causes the arm 18 to move away frombutton 86a whereby the switch closes to start the motor. When the arm I4is driven to a point where the blade 16 disengages from the threads onthe feed screw and engages the bearing area 68 and the spring cap 12moves lever 75 counterclockwise and arm 18 depresses button a. motor.

The follower 63 engages with and rotates upon a cam means 8|. This camcontrols the movement of the follower in a direction perpendicular toits axis of rotation. The cam means 8| includes a bracket 82 screwed tothe top of the base l0, Figs. 1, 3 and 8. An adjusting screw 82bcooperates with a knurled nut 83 and extends up through the top of basel0 and through the bracket. The cam shoe 84 is fastened to the top ofthe adjusting screw 82b and is raised or lowered relative to the bracketwhen the nut 83 is adjusted. This shoe is formed with a decliningsurface 8411 (Fig. 3) extending longitudinally in the direction of theaxis of rotation of the follower 63. This surface forms an arc of acurve extending transversely to the axis of rotation of the follower 63,as indicated at 84b in Fig. 8.. In operation, the periphery of thefollower 63 is placed first in contact with the high portion of the camshoe 84., As the feed screw 61 drives the arm l4, the follower movesdown over the surface 84a of the shoe from the high to the low point andgradually lowers the arm and lens blank.

Theabrading element for the lens blank comprises, in general, a quillhousing 9| having a centrally positioned spindle shaft 92, Fig. 3. Thisshaft is secured at one end within the upper part of the base 0. Thequill housing 9| is supported at each end on bearings 93 mounted on theshaft 92. This quill housing 9| thus rotates freely. The quill housing9| is enlarged to provide a drum portion 94 which is encircled by aremovable abrasive belt 95. This belt is substantially the full width ofthe drum as shown in Fig. 3. In one form, this belt is constructed of aheavy fabric-like material having a coating of silicon grit on its outersurface. The belt is held on the drum by the end flange member 91 whichis fastened to the end of the drum with screws. The drum 94 isconstructed with a peripheral curve having substantially the same radiusof curvature as the arc of surface 842) (Fig. 8) on the cam shoe so thatthe lens blank will be edged to conform to the pattern of the follower63. If desired, a diamond wheel of the same size can be substituted forthe drum 94 and belt 95.

A groove is formed in the opposite end of the quill housing 9| toreceive a belt |0|.' This belt is directly driven from the motor 38 androtates the drum at a rate of speed of the order of 5000 R. P. M. Theshaft means for driving the holder provides for rotating the lens blankin a direction opposite to the direction of rotation of the drum 94 andat a rate of speed of the order of 2 R. P. M. Then when the edge of thelens blank 42 comes into contact with the abrasive surface of the belt95, a cutting engagement is obtained.

A suction pump 05, Fig. 3, is also driven from the motor 38. A recessedarea I66 is provided in the top of the base beneath the drum 94 toreceive the cuttings and dust from the grinding operations. Thesecuttings are removed through an opening in the surface I66 whichconnects with an adapter 101. A hose, not shown, connects between theadapter and the suction inlet |08 of the pump.

In Fig. 9 a modified construction is illustrated. This construction isadapted to provide for bevel edging the lens blank 42. The feed screw 61is provided with a second bearing surface 5 terminating in a head 6. Thecam shoe surface 84a is. extended to provide a recessed horizontalSwitch 80' then opens and stops the surfaceI II. Infadditionto theabrading element 95 another abrading element 9511 having 'a V notchlcu'ttingsurface Il8 isfprovided. The overall depthof' the notch II 8isequal to or slightly greater than the distance which the surface II"! isbelow thesurface Il9ofthe cam shoe so that the over-all diameters 'ofthe lens blank will'not be changed by further .cutting. In operation,when thefollower' 63 reaches the'lowest part of the cam surface 84a,i.e., surface'IlS, the lens blank has moved across the surface 95 of theabradin'g' element .and is' cut-down toithe desired shape anddimensions. I Further movement ofthe arm -'I4 is prevented by engagementof blade I with the head 69. The arm l t is raised bythe operator tofree blade I6 from engagement with head 59 and the arm sw-unghorizontally-so that blade 'I5 engages 'between the'heads69 and IIB.This movement -is sufficient to bring the follower 63- into'engagement'with thesurfa'ce -I I1 and to center thelens blank 42 in theV-notch I E8 of 'the abrading element 95a. Rotationof the abradingelement cuts abevel edge on each side-of the lens blank.

A further modification is Shown' inF-ig'lO. In this form, the bevel edgecan be completed as a continuous part of the cutting operations. The camsole surface 84a -is extended to provide a downwardly sloping surfaceI20 terminating in a horizontal surface I2I having a stop member I22.'Where, for example, the bevel on the lens blank is-to be 45 degrees,the slope of surface I20 is" 22 degrees from vertical. The abradingelement95a is provided with a'V-notch I I8a having oppositely disposedsides I23 and 12311 sloping at 45 degrees. 'The over-all depth of thenotch I Illa is equal to the depth of the cam surface I2I below surface[I9 so that the cutting to produce the bevel edges does not reducethe-over-all finished diameters of the lens blank. 'Inoperation, thefollower 03 moves from thesurfa'ce I-I9 down theslope of surface I20.This movement'causes the lens blank to-movedown the slope-of surfaceI230, and the rotation of the abra'dingelement produces a bevel edge onone side of the'lens blank. -As the follower 53 moves acrosssurfaceI2I,the other side of the lens blank is brought into contactwith-the-surface I23 which' produces a bevel edge on that side-of thelens blank. Engagement of the-follower 63 with the stop member I22prevents the lens blank from being too deeply'cut or bevelledby'engagement with-surface I23.

Another formof construction for bevel edging is shown in Fig. 11. Thecam shoe 84 is provided with a surface I24 which slopes upwardly at '30degrees from horizontal where the beveledge is to be at 45 degrees. Ahorizontal surface I20 and an oppositely'disposed surface I28sloping'at'22 /2 degrees from vertical are also provided. The abradingelement 95a is provided with a surface I30 slopin upwardly at-45degrees, a horizontal surface I3I and'a surface I32 at 45 degreesoppositely disposed from surface I30. In operation, as the follower 63moves up the surface I24 the lens blank is brought into contact withsurface I30 and gradually-cut down to the desired overall dimensions andshape. As shown, the lens blank edge in contact with surface I30 will beout at an angle of 45 degrees. 'Movement-of the follower across surface-I26 provides for removing any tail that may be formed from the cuttingon surface I30. Movement of the follower across surface I26 carries thelens blank across surface I3I. Further movement of the 8 follower downthe surface 128, i. e., at'22 /2 degrees, brings the'other edge of lensblank into contact with'the 45 degree surface I32 and produces afinished bevel of 45;degrees onthat edge.

In operation, the arm I4 is :raised manually and swung backat rightangles to the top of base If). Such movement disengages the feed screw61 from the knife blade I6. The lever I5'is then moved by the springcaps I2 to a position opening the switch and stopping motor 38. In theraised'position the underside of arm member I4 'is'exposed. Thisfacilitates either mounting or removing a lens blank.

When a lens blank is mounted in the holder, the arm'l4 is lowered fromthe raised position. The arm I4 is swung parallel to the top of base I0until the'follower 63 rides on the high part of the cam shoe-84. Theknife blade I6 is adjusted so that in this position it then engages'between the threads at the end of the feed screw 61 farthest'from thehead 69. This engagement moves the lever "I5 in a direction which causesthe motor switch to close. The motor, in turn, drives the shafts I6, 21and 28, the quill 9|, and the blower I05. Shaft 28 rotatesboth the lensholder and the follower, and drives the feed screw 61. The rotation ofthe feed screw, while in engagement with the knife blade I6, causes thesupport II to move about the pivot '24. This movement causes therotating follower 53 to move gradually down the surface 84a, of the camshoe. The lens blank rotates in synchronism with the follower and isalso responsive to the movement of the follower at right angles to itsaxis of rotation, since the supporting arm I3 is free to pivot aboutshaft l6. This construction provides for gradually cutting the lensblank down to the desired shape as the lens blank moves down intocontact with the rotating belt 05 and across the belt from one edgethereof to the other. A's the edging of the lens blank progresses, thearm I4 swings in an are about the pivot 24. The radius of this are issuch that when the edging of the lens blank is completed the axis ofrotation of shaft 28, carrying the lens blank and follower, is parallelto the axis of 'rotationof the abrading element. This constructionprovides for accurately edging the lens blank'according to the patternof the follower.

When'the follower moves across the low part of 'the'cam shoe surface84a, the edging of the lens blank is completed. The arm 14 has thenmoved a sufficient distance for the threads on theifeed screw todisengage from the knife blade 16. .Blade'16 thenengages adjacent thebearing'area68 and head 69 prevents further longitudinalmovement'of thescrew with respect to the blade I6. The lever I5 then is no longer heldin-a position to maintain the motor switch closed and the motor stops.The operator then raises the arm 13 to'remove the finished lens blank,inserts a new lens blank, and again lowers the arm to repeat theoperation.

While the forms of embodiments of the present invention as hereindisclosed constitute preferred forms, it is to be understood that otherforms might be adopted, all coming within the scope of the claims whichfollow.

We claim:

1. In a lens edging machine, in combination, a base; an abradingelement; a rotating shaft carried by the base and carrying the abradingelement; -a second rotating shaft having a threaded portion; a lensblank holding element carried by the second shaft; means for rotatablysupporting the second shaft with the axisthereof substantially parallelwith the axis of the first shaft, said means including a pivot on thebase having an axis disposed substantially at right angles to the axisof the first shaft, and an arm pivotally mounted on the pivot andextending toward the first mentioned shaft and carrying the secondmentioned shaft; a member on the base received by the groove of thethreaded portion of the second shaft, for causing swinging movementto beimparted to the arm when the second shaft is rotated; and means forrotating the shafts.

2. In a lens edging machine, in combination, a base; an abradingelement;a rotating shaft carried by the base and carrying the abrading element;a second rotating shaft having a threaded portion; a lens blank holdingelement carried by the second shaft; means for rotatably supporting thesecond shaft with the axis thereof substantially parallel with the axisof the first shaft, said means including a pivot on the base having anaxis disposed substantially at right angles to the axis of the firstshaft, and an arm pivotally mounted on the pivot, said arm including apivot disposed on an axis transverse to the axis of the first mentionedpivot and including a lever pivotally carried by the second mentionedpivot and extending toward the first mentioned shaft and carrying thesecond mentioned shaft; a member on the base received by the groove ofthe threaded portion of the second shaft, for causing swinging movementto be imparted to the arm when the second shaft is rotated; and meansfor rotating the shafts.

3. In a lens edging machine, in combination, a base; an abradingelement; a rotating shaft carried by the base and carrying the abradingelement; a second rotating shaft having a threaded portion; a lens blankholding element carried by the second shaft; means for rotatablysupporting the second shaft with the axis thereof substantially parallelwith the axis of the first shaft, said means including a pivot on thebase having an axis disposed substantially at right angles to the axisof the first shaft and an arm pivotally mounted on the pivot, said armincluding a rotating driving shaft disposed on an axis transverse to theaxis of the pivot, said arm including a lever pivotally carried by thelast mentioned shaft and extending toward the first mentioned shaft andcarrying the second shaft; gearing between the shafts carried by thearm; a member on the base received by the groove of the threaded portionof the second shaft for causing swinging movement to be imparted to thearm when the second shaft is rotated; and means for rotating the shafts.

4. In a lens edging machine, in combination, a base; an abradingelement; a rotating shaft carried by the base and carrying the abradingelement; a second rotating shaft having a threaded portion; a lens blankholding element carried by the second shaft; means for rotatablysupporting the second shaft with the axis thereof substantially parallelwith the axis of the first shaft, said means including a pivot on thebase having an axis disposed substantially at right angles to the axisof the first shaft, and an arm pivotally mounted on the pivot, said armincluding a bearing support slidably carried on the base, said armincluding a shaft carried by the bearing support, the last mentionedshaft being V disposed on an axis transverse to the axis of the 1 firstmentioned pivot, said arm including a lever pivoted on an axistransverse to the axis of said pivot and extending toward the firstmentioned shaft and carrying the second shaft; gearing between theshafts carried by the arm; a member on the base received bythe groove ofthe threaded portion of the second shaft for causing swinging movementto be imparted to the arm when the second shaft is rotated; and meansfor rotating the shafts.

5. In a lens edging machine, in combination, a base; an abradingelement; a rotating shaft carried by the base and carrying the abradingelement; a second rotating shaft; a lens blank holding element carriedby the second shaft; means for rotatably supporting the second shaftwith the axis thereof substantially parallel with the axis of the firstshaft, said means including a pivoton the base having an axis disposedsubstantially at right angles to the axis of the first shaft, and an armpivotally mounted on the pivot, said arm including a bearing supportslidably carried on the base, said arm including'a rotating drivingshaft carried by the bearing support and disposed on an axis transverseto the axis of the pivot and intermediate thepivot and the firstmentioned shaft, said arm including a lever pivoted on the arm on anaxis transverse to the axis of said pivot and extending toward the firstmentioned shaft and carrying the second mentioned shaft; gearing betweenthe shafts carried by the arm; a driving wheel on the third mentionedshaft; a belt on the wheel; and means for driving the belt, the axis ofthe pivot of the arm when projected substantially intersecting theperipheral portion of the wheel at a point substantially most remotefrom the means for driving the belt.

6. In a lens edging machine, in combination, a base; an abradingelement; a rotating shaft carried by the base and carrying the abradingelement; a second rotating shaft; a lens blank holding element carriedby the second shaft; means for rotatably supporting the second shaftwith the axis thereof substantially parallel with the axis of the firstshaft, said means including a pivot on the base having an axis disposedsubstantially at right angles to the axis of the first shaft, and an armpivotally mounted on the pivot and extending toward the first mentionedshafts, said arm including a bearing support slidably carried on thebase, a rotating driving shaft carried by the bearing support anddisposed on an axis transverse to the axis of the pivot and intermediatethe pivot and the first mentioned shaft; gearing between the shaftscarried by the arm; a driving wheel on the third mentioned shaft; a belton the wheel; and means for driving the belt, the axis of the pivot ofthe arm when projected substantially intersecting the peripheral portionof the Wheel at a point substantially most remote from the means fordriving the belt.

'7. In a lens edging machine, in combination, a base; an abradingelement; a rotating shaft carried by the base and carrying the abradingelement; a second rotating shaft having a threaded portion; a lens blankholding element carried by the second shaft; means for rotatablysupporting the second shaft with the axis thereof substantially parallelwith the axis of the first shaft, said means including a pivot on thebase having an axis disposed substantially at right angles to the axisof the first shaft, and an arm pivotally mounted on the pivot andiextending toward the' first mentioned shaft: and carrying the secondmentioned shaft; means for: rotatin the second mentioned shaft; andmechanism: for controlling the lastnamed means' including' a controllerhaving a member received by the groove: of the: threaded portionof: thesecond mentioned shaft and: movable to eifect': starting and stopping ofthe shaft"; rotating means by engagement and disengagement,respectively, of the threaded portion of the second'mentioned shaft withsaid member.

8. In a lens edging machine; incombination, a'base; an abradingelement;- a rotating'shaft carried by the base and 'carryingthe abradingelement; a secondrotatingshaft having a threaded portion; a lensblank-holding element. carried by thesecond shaft; means for" rotatablysupportingthe second shaft with the axis there.- of substantiallyparallel with the axis of the'first shaft, said means including a pivoton the. base having an axis disposed" substantially atright angles totheaxis-of the first-shaft, and v an arm pivotally mounted on: the pivot,said arm including a pivot disposed on an axistransverseto the axis ofthe first mentioned pivot= and: including a leverpivotally-oarried byvthe= second-I mentioned pivotandi extending. toward the first mentionedshaft and'i carrying: the-second: mentioned. shaft; means for rotating:the: second; mentioned. shaft; and mechanisma for; controlling thelastnamed means: including a; controller having a member received bythegroovexoff theethreadedportion of the second mentionedshaftandmovableto effect starting and stopping of ,theshaf t. rotating means byengagementand disengagement, respectively, of the threadedportionofithe: second mentioned shaft with said member.

ROBERT. E. ALLEN.

WILLIAM. F. UTZINGER.

REFERENCES CIT-ED The following references are of record in the fileof"this patent:

UNITED STATES PATENTS Number Name; Date- 375,332; Bessomet a-l.,Dec..27-, 1887 1,455,863; Bugbee: .May 22, 192-3 1,457,855 RichardsorrJune 5, 1923 1,558,167 Herricko Oot.,24, 1925 1,713,622 Rakel May 21,1929 2,164,155 Lemay .June 27-, 1939 2,321,382 Harper June 8, 1943

